iieprodudivc Organs of Spams Ceatrodontus. 27 



space. Some of the small yellow opaque eggs exhibit the white 

 embryo on the outside. 



Many of the eggs, then, found free in the ovar}- are larger than when 

 the}^ are in follicile. They have imbibed some fluid. In the ovary 

 along with the free eggs there is a coagulable fluid, in which green 

 oil globules are floating. This is, I consider, the fluid which is secreted 

 in the urinary bladder of the male fish, and which is introduced into the 

 ovary along with the sperm. The eggs when they escape from the 

 follicile imbibe this fluid, and in this way a perivitelline space becomes 

 formed. The remains of the fluid present among the eggs is found in 

 the preserved ovar}- in the form of a granular solid, which is in the 

 form of strings filling the interstices between the eggs, or is attached 

 to the wall of the ovary in a honeycomb form (Figs. 57 and 58). It 

 can be easily removed from the wall, but it has often attached to it a 

 delicate skin which has probably been torn off the ovarj- or its wall. 

 The material is translucent, and it encloses vesicles of various sizes ; 

 the latter resemble oil globules. In a preserved urinary bladder of a 

 male fish the j'ellow fluid was coagulated to a granular powder. 



The earl}" embryos show no pigment. In one in which the tail 

 nearl}- reached the head, no pigment was made out. The eyes were 

 visible : the head was thick dorso-ventrally (Fig. 67). 



When ready to hatch the embryos show pigment. In one (Fig. 71) 

 the eyes ccmtained black pigment, biit no other pigment was observed. 

 The yellow oil ghdjule was present and Avas still large. In others, 

 however, a row of black spots was visible along the ventral edge of 

 the post-anal body, but not extending as far as the end of the tail. 



The black eyes of the embryos shining through the wall of the 

 yellow ovarj' cause the latter to appear greenish. 



The embryos in an ovary appeared to be all of about the same 

 stage of development. 



After the larvse escape from the egg they remain in the ovary 

 until the yolk is absorbed. Fig. 68 represents a larva which was 

 found hatched in an ovary containing embryos still in the egg. The 

 peculiar condition of the anterior end of the little fish is seemingly 

 due to the fact that that region is still enveloped in the zona. In its 

 bent condition the larva extended 3'25 mm. 



A ventral view of the anterior end of a larva is shown in Fig. 69. 

 The mouth is a small pore situated between the eyes. The eyes 

 approach one another closely on the ventral surface. The round 

 pectoral fin Q/.) is small. There are no jaws. In another specimen 

 a semi-circle could be traced across the mouth region. This may 

 indicate the line of separation betM-een the jaws. A larva is 

 exhibited in side view in Fig. 77. It had been preserved. The eyes 

 were deeply pigmented. It had a characteristic blunt head. The 

 marginal fin was composed of little round cells. The tail fin had a 

 somewhat ragged edge. Pieces of cuticle were lying loose at sk. 



Some larv^ measured from o-7 to 4-3 mm. in length. The example 

 3"7 mm. long was bent. A little black pigment was present over the 

 eyes and on the region of the rectum. A row of pigment spots was 

 present on the dorsal and ventral edges of the hind half of the body. 

 The ventral row commenced a short distance behind the anus and 

 extended back to the beginning of the tail fin. Sometimes the 

 pigment on the post-anal body is not made out. A couple of the 

 largest larvge had the jaws formed. 



